CN107741624B - A split type low power consumption small auto focus brake - Google Patents

Abstract

The invention belongs to the technical field of camera brakes, and particularly relates to a split type low-power-consumption small automatic focusing brake which comprises a shell, a spring, an image sensor carrier, at least one magnet, at least one independent coil and an elastic circuit board, wherein the spring, the image sensor carrier and the elastic circuit board form a spring vibrator system with an axial displacement freedom degree, the at least one magnet is arranged on the inner wall of the shell, the independent coil is arranged on the image sensor carrier and corresponds to the magnet, and the independent coil is subjected to an ampere force action in a magnetic field of the magnet after being electrified. The brake structure of the invention can not generate nonlinear friction force and has the characteristics of dust prevention and good heat dissipation effect.

Description

A split type low power consumption small auto focus brake

technical field

The invention belongs to the technical field of camera brakes, and in particular relates to a split-type low-power consumption small automatic focusing brake.

Background technique

In recent years, portable photographing devices with an autofocus function have become very popular, and have basically become a standard function of photographing devices. When the subject is at different distances during the shooting process, the autofocus function can effectively improve the resolution of the closer subject in the image and improve the quality of the close-up photo. On the other hand, the autofocus function can blur the image of objects at other distances, so that the subject can be more prominent in the photo.

The traditional AF system achieves the effect of changing the Optimal Object Distance by moving the entire lens or the position of certain elements in the lens. In recent years, traditional mainstream actuators can precisely change the optimal object distance in a short period of time to achieve fast focusing and improve focusing accuracy.

Another type of AF system is the sensor-moving type. The image sensor is driven by an actuator to change the distance between the lens and the image sensor to achieve the effect of AF. Sensor-moving actuators have an advantage in power consumption over lens-moving actuators, mainly because the parts that need to be moved during autofocus are generally lighter.

Since the weight and size of the lens components to be moved by the lens-shifting actuator are usually large, a higher-power and larger-sized actuator is required to drive, which not only increases the weight and size of the camera, but also reduces the size of the camera. The battery life of the device.

Some small shooting devices equipped with heavier wide-angle lenses, such as small action cameras, cannot bear the extra weight and size brought by the lens-moving actuator, so the actuator cannot be added, which affects the image resolution during close-up photography.

On the other hand, in mainstream interchangeable lens shooting devices, such as digital single-lens reflex cameras, the lens shift actuator is set in the lens. When the camera is equipped with multiple lenses, each lens needs to be equipped with an actuator, which greatly improves the The cost to be paid, and the added weight of the brake itself is inconvenient to carry, which increases the load of the photographer's equipment and affects the mobility of the shooting.

Although the sensor mobile actuator has theoretical advantages in power consumption and size, the actuator technology in this field is not mature enough, and there are many shortcomings. At present, the sensor mobile actuator usually adopts a contact limit structure to obtain a displacement degree of freedom of an axis parallel to the optical axis. The limit structure will inevitably increase the non-linear friction during the autofocus process, which will affect the accuracy of the autofocus. In addition, friction or impact in the actuator during a drop or autofocus may cause the internal structure to shatter, which can affect image quality if the debris falls over the image sensor.

In addition, since the image sensor in the actuator needs to have a certain space for movement, the circuit board under the image sensor cannot be tightly attached to the housing, which is detrimental to heat dissipation. In the prior art, another effective heat dissipation path is not added in the design of the actuator, and poor heat dissipation of the image sensor will cause more image noise, or even fail to work normally.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a split type low-power consumption small auto-focusing brake, so as to solve the problem of nonlinear frictional force generated during the auto-focusing process by the limiting structure of the sensor movable actuator in the prior art, which affects the auto-focusing. problem of accuracy.

Another object of the present invention is to provide a split type low power consumption small auto focus brake, so as to solve the problem of debris and contamination of images caused by friction or impact in the actuator during the brake drop or auto focus process in the prior art Problems with the sensor surface.

Another object of the present invention is to provide a split-type low-power consumption small auto-focusing brake, so as to solve the problem of poor heat dissipation effect of the sensor movable actuator in the prior art, and the image sensor will have a lot of image noise or even cannot work normally. question.

The present invention provides a split-type low power consumption small auto-focusing brake, comprising a casing, a spring, an image sensor carrier, at least one magnet, at least one independent coil and an elastic circuit board, the spring is provided on the top of the casing The inner surface of the casing can be elastically deformed along the vertical axis direction of the casing. The elastic circuit board is arranged transversely to the lower part of the casing under the spring. One end of the image sensor carrier is connected to the the spring is connected, and the other end is connected to the elastic circuit board, and the spring, the image sensor carrier, and the elastic circuit board form a spring vibrator system with an axial displacement degree of freedom;

The at least one magnet is arranged on the inner wall of the housing, the independent coil is arranged on the image sensor carrier and is arranged corresponding to the magnet, and the independent coil is subjected to ampere in the magnetic field of the magnet after being energized force action.

As a preferred mode of the present invention, an image sensor is provided on the elastic circuit board.

As a preferred mode of the present invention, it further includes a positioning seat, the positioning seat is abutted against the inner top surface and the inner wall of the housing, and the positioning seat fixes the at least one magnet on the inner wall of the housing;

The spring is a spring sheet, one end of the spring sheet is fastened at the connection between the inner top surface of the housing and the positioning seat, and the other end is connected with the image sensor carrier.

As a preferred mode of the present invention, the flexible circuit board includes first to fifth rigid circuit boards, a first flexible circuit board, and a second flexible circuit board, and the first rigid circuit board mounts the image sensor and the first flexible circuit board. The periphery of a rigid circuit board is connected to the first flexible circuit board, the four corners of the first flexible circuit board are respectively connected to the second to fifth and fifth rigid circuit boards, and the second to fifth and fifth rigid circuit boards are respectively connected. The five rigid circuit boards are also respectively connected with the second flexible circuit boards, and the second flexible circuit boards are provided with sockets.

As a preferred mode of the present invention, the image sensor carrier is rigidly connected to the first rigid circuit board, and the second to fifth rigid circuit boards are also rigidly connected to the positioning seat, respectively.

As a preferred mode of the present invention, it also includes a cylindrical baffle, the cylindrical baffle is arranged coaxially with the vertical axis of the casing, and its upper end is connected with the upper surface of the casing or with the casing The upper surface of the device is integrally formed, and there is a gap between the cylindrical separator and the image sensor carrier.

As a preferred mode of the present invention, the cylindrical separator is made of a material with excellent magnetic and thermal conductivity, and its surface color is a dark color with a strong ability to absorb heat radiation.

As a preferred mode of the present invention, the height of the cylindrical separator is greater than one third of the height of the magnet.

As a preferred mode of the present invention, when the number of the magnets is greater than 1, the same-named magnetic poles of the magnets are arranged opposite each other. .

As a preferred mode of the present invention, the image sensor carrier is further provided with a limiting boss on the outer periphery; the upper surface of the housing and the upper surface of the positioning seat are provided with positioning holes with overlapping holes.

The invention uses the ampere force generated in the magnetic field by the energized independent coil on the image sensor to drive the image sensor carrier to move on one axis, and when the current flow direction is changed, the motion detection of the image sensor carrier can be changed, thereby realizing the automatic focusing of the camera. Function, the contact point of the support structure of the present invention does not have a contact point with friction force, and there is no nonlinear friction force during the braking process, the focusing is accurate, and the image is clear.

In addition, the image sensor carrier of the present invention is also provided with a limit boss on the periphery, so that there will be no violent lateral impact and vertical friction between the image sensor carrier and the cylindrical partition during the brake drop or auto-focusing process, avoiding the image sensor carrier. The possibility of breakage and fragmentation between the carrier and the cylindrical spacer reduces the possibility of debris near the image sensor location and the possibility of debris contaminating the image sensor location.

Furthermore, the present invention is also provided with a cylindrical baffle, which is connected with the outer casing or integrally formed, and has the functions of absorbing heat radiation, conducting heat, preventing dust and preventing electromagnetic radiation, and can effectively dissipate the work of the brake. The generated heat avoids the problem of image noise or even the machine not working properly due to overheating of the brakes.

Finally, the present invention is an actuator driven by electromagnetic force, which does not require a complex mechanical transmission structure, and the upper surface of the housing and the upper surface of the positioning seat are provided with positioning holes with overlapping holes, which can realize the separation of the brake and the lens. The effect of connection, the split structure can improve the versatility of the present invention and save the user cost. Therefore, the invention has the characteristics of compact structure, convenient assembly, small size, light weight, low cost, low power consumption and good versatility, and is suitable for mass production and popularization.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Fig. 1 is the outline structure schematic diagram of the embodiment of the present invention;

2 is an exploded view of the structure of an embodiment of the present invention;

3 is a structural cross-sectional view of an embodiment of the present invention;

4 is a schematic structural diagram of an elastic circuit board according to an embodiment of the present invention;

5 is a schematic diagram of a dustproof and heat dissipation principle according to an embodiment of the present invention;

6 is a schematic structural diagram of assembling a camera lens according to an embodiment of the present invention;

FIG. 7 is a sectional view of the structure of assembling a camera lens according to an embodiment of the present invention;

8 is a schematic diagram of a focusing principle according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the focusing principle of the embodiment of the present invention with the lens moving brake.

Among them, 1. Upper shell, 2. Lower shell, 3. Elastic circuit board, 4. Image sensor, 5. Independent coil, 6. Spring sheet, 7. Positioning seat, 8. Magnet, 9. Image sensor carrier, 10. Limiting boss, 11. Cylinder-shaped partition, 12, First rigid circuit board, 13, First flexible circuit board, 14, Second rigid circuit board, 15, Third rigid circuit board, 16, No. Fourth rigid circuit board, 17, fifth rigid circuit board, 18, second flexible circuit board, 19, socket, 20, lens carrier, 21, camera lens, 22, positioning hole.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

An embodiment of the present invention provides a split-type low-power small autofocus actuator, as shown in FIGS. 1 to 7 , including a housing, a spring, an image sensor carrier 9 , at least one magnet 8 , at least one independent coil 5 , and an elastic circuit plate 3. The spring is arranged on the inner surface of the top of the casing and can be elastically deformed along the vertical axis direction of the casing. Below the spring is an elastic circuit board 3 which is transversely placed on the lower part of the casing. One end of the image sensor carrier 9 is connected to the spring, the other end is connected to the elastic circuit board 3 , and the image sensor 4 is rigidly connected to the surface thereof. The elastic circuit board 3 is composed of a rigid circuit board and a flexible circuit board, and the flexible circuit board refers to an elastic circuit board with a higher stiffness coefficient. The spring, the image sensor carrier 9, and the elastic circuit board 3 form a spring vibrator system with one-axis displacement degree of freedom, and the direction of the displacement degree of freedom of the spring vibrator system is parallel to the optical axis of the camera.

At least one magnet 8 is fixed on any inner wall of the casing, the casing and the magnet 8 form an immobile structure, and the spring vibrator system vibrates on the basis of the immobile structure. The independent coil 5 is wound on the image sensor carrier 9 and is arranged corresponding to the magnet 8, and the coils in the independent coil 5 can be connected in series or in parallel on the circuit. After the independent coil 5 is energized, an ampere force F parallel to the optical axis of the camera is generated in the magnetic field of the magnet 8, and the image sensor carrier 9 is moved along the vertical axis direction of the casing by the action of the ampere force F, and is placed on the image sensor carrier 9. The image sensor 4 can be displaced accordingly. By changing the current size and direction of the coil, the magnitude and direction of the ampere force F can be changed, thereby changing the distance between the camera lens 21 and the image sensor 4 and the optimal object distance. The effect of autofocus. When the independent coil 5 is powered off, the ampere force F disappears, and the spring vibrator system is restored to the initial state by the elastic force, that is, the focus of the camera returns to the initial position.

In order to facilitate the manufacture and assembly of the present invention, the actuator and the camera lens are separated, and different types of lenses can be arranged above and outside the actuator, and the optical axis of the lens and the optical axis of the image sensor 4 are arranged in parallel. In addition, the casing is a rectangular casing and adopts a split design, which is divided into an upper casing 1 and a lower casing 2 .

On the basis of the above-mentioned embodiment, another embodiment further includes a positioning seat 7. The positioning seat 7 is tightly abutted on the inner top surface and inner wall of the upper casing 1, and plays a role in fixing the spring and the magnet 8, so that the shell The body, the magnet 8 and the positioning seat 7 form a stationary structure. The spring of the present invention can be selected as a leaf spring, that is, a spring leaf 6. One end of the spring leaf 6 is fastened at the connection between the inner top surface of the upper casing 1 and the positioning seat 7, and the upper and lower parts of the fastened spring leaf 6 are There is a certain space for elastic deformation of the spring sheet 6 , that is, the fixing structure of the spring sheet 6 is a cantilever beam structure, and the other end of the spring sheet 6 is also fixedly connected to the image sensor carrier 9 .

Another embodiment based on the above-mentioned embodiment, referring to FIG. 4 , the elastic circuit board 3 includes a first rigid circuit board 12 , a second rigid circuit board 14 , a third rigid circuit board 15 , and a fourth rigid circuit board 16 . , the fifth rigid circuit board 17 , the first flexible circuit board 13 , the second flexible circuit board 18 , the first rigid circuit board 12 is equipped with the image sensor 4 and the periphery of the first rigid circuit board 12 is connected to the first flexible circuit board Connection 13, the four corners of the first flexible circuit board 13 are respectively connected with the second rigid circuit board 14, the third rigid circuit board 15, the fourth rigid circuit board 16, and the fifth rigid circuit board 17. The second rigid circuit board 14, The third rigid circuit board 15 , the fourth rigid circuit board 16 , and the fifth rigid circuit board 17 are respectively connected to the second flexible circuit board 14 , and the second flexible circuit board 14 is provided with a socket 19 .

The reason why the spring sheet 6, the image sensor carrier 9, and the elastic circuit board 3 can form the spring vibrator system is because the periphery of the first rigid circuit board 12 is connected to the first flexible circuit board 13, and the first flexible circuit board 13 is made of elastic material And has a relatively strong stiffness coefficient, so the first rigid circuit board 12 has a certain degree of freedom in space, and can ensure at least one degree of freedom of axial movement. Four rigid circuit boards are connected to the four corners of the first flexible circuit board 13. These four rigid circuit boards are located at the junction of the positioning seat 7 and the housing, and the four rigid circuit boards are rigidly connected by the housing and the positioning seat 7. , that is, the fixing of the elastic circuit board 3 can be realized. The second flexible circuit board 18 is exposed outside the casing, and can be connected to sockets 19 or various circuit interfaces, so that the present invention can obtain power from the outside or send and receive information.

On the basis of the above-mentioned embodiment, another embodiment, as shown in FIG. 5 , further includes a cylindrical separator 11 , which is made of a material with excellent magnetic and thermal conductivity (eg, steel). The cylindrical baffle 11 is arranged coaxially with the vertical axis of the casing, and its upper end is connected with the upper surface of the upper casing 1 to form a cylindrical body extending downward from the upper surface of the upper casing 1. That is, the optical path from the camera lens 21 to the image sensor 4 . The outer portion of the cylindrical body is adjacent to the image sensor carrier 9 and has a certain gap with the image sensor carrier 9 to prevent dust or braking hysteresis caused by friction between the spring vibrator system and the cylindrical separator 11 when vibrating. The cylindrical baffle 11 can play four functions. One is dustproof. The cylindrical baffle 11 can block the dust intruding from the joint of the brake housing. The dust should enter the surface of the image sensor from the outside of the image sensor carrier 9. It must pass through the narrow and slender channel between the cylindrical partition 11 and the image sensor carrier 9 , which greatly increases the difficulty of dust entering the surface of the image sensor 4 and reduces the possibility of the surface of the image sensor 4 being contaminated by dust. The second is to enhance the heat dissipation capability. Since the image sensor 4 and the independent coil 5 will generate heat during operation, when the temperature of the image sensor 4 is too high, image noise may occur or even cannot work. Therefore, when the image sensor 4 and the independent coil 5 are close to the The cylindrical spacer 11 is arranged at the position, which can absorb the thermal radiation emitted by the image sensor 4 and the independent coil 5. In addition, the cylindrical spacer 11 is connected to the brake housing, so the cylindrical spacer 11 can conduct heat to the case. The body dissipates heat to the outside, improving the overall heat dissipation capacity of the brake. The third is to reduce external high-frequency electromagnetic interference. The material of the cylindrical separator 11 has magnetic permeability (such as steel), which can shield the image sensor 4 around the image sensor 4 and reduce the impact of external equipment on the image sensor. 4 electromagnetic interference. The fourth is to increase the ampere force F received by the independent coil 5. The cylindrical separator 11 has a magnetic permeability, which can increase the density of the magnetic field flowing through the independent coil 5. Enhancing the magnetic field density helps to increase the ampere force F received by the independent coil 5. .

Further, the cylindrical separator 11 may also be integrally formed with the upper surface of the upper casing 1 , and the integrally formed structure not only facilitates the manufacture and assembly of the product, but also makes the product more dustproof and thermally conductive.

In another embodiment based on the above-mentioned embodiment, the surface color of the cylindrical separator 11 is a dark color with strong ability of absorbing heat radiation, such as dark black, dark gray or dark blue. The dark color can be the color of the material of the cylindrical separator 11 itself, or the color that appears after processing, and the coloring processing method can be electroplating or painting.

In another embodiment based on the above-mentioned embodiment, the height of the cylindrical separator 11 is greater than one-third of the height of the magnet 8, and the larger the height of the cylindrical separator 11, the better the dustproof, thermal conductivity, and anti-interference capabilities of the cylindrical separator 11. However, the actual assembly size of the cylindrical spacer 11 should not exceed the distance from the spring sheet 6 to the image sensor 4 .

On the basis of the above-mentioned embodiment, another embodiment includes two pairs of magnets 8, and each magnet 8 is respectively located on the inner side wall of the casing. The poles of the same name of the oppositely arranged magnets 8 are opposite, and when the current passes through the independent coil 5, the ampere force F generated is in the same direction. By changing the direction and magnitude of the current, the direction and magnitude of the ampere force F can be changed, so as to achieve the effect of displacement of the image sensor 4 along the optical axis, and realize the automatic focusing function.

In another embodiment based on the above-mentioned embodiment, the image sensor carrier 9 is also provided with a limit boss 10 on the outer periphery, so as to ensure that the image sensor carrier 9 and the cylindrical partition 11 will not appear between the image sensor carrier 9 and the cylindrical partition plate 11 during the drop of the brake or the automatic focusing process. The violent impact in the lateral direction and the severe friction in the longitudinal direction avoid the possibility of breakage and fragmentation between the image sensor carrier 9 and the cylindrical separator 11, and reduce the possibility of debris near the image sensor, and the debris contaminates the image sensor. Possibility of location.

Further, the upper surface of the housing and the upper surface of the positioning seat are provided with positioning holes 22 with overlapping holes, and the positioning holes 22 are used for installing the lens carrier 20 to increase the precision of the mechanical connection. The positioning hole 22 also facilitates the mechanical connection between the present invention and other external components, making the present invention universal.

In the present invention, the current of the independent coil 5 is driven by the autofocus control chip, and the control chip is electrically connected to the independent coil and the elastic circuit board 3 . The control chip can be arranged on the flexible circuit board 3 , or can be arranged outside the brake and connected to the flexible and hard circuit board 3 through the socket 19 .

The focusing principle of the present invention is shown in FIG. 8 . Assuming that the distance between the lens and the image sensor is Dinf (as shown in the figure) when focusing at a far distance, when a lens-moving actuator is used for close-focusing, the lens-moving actuation The sensor will raise the lens by ΔD1, and the distance between the lens and the image sensor will become Dinf+ΔD1, achieving a smaller optimal object distance. When using the actuator in the present invention to focus close (as shown in the figure), the actuator will lower the image sensor by ΔD2, and the distance between the lens and the image sensor will become Dinf+ΔD2, achieving a smaller optimal object distance , when ΔD1≈ΔD2, the actuator in the present invention can achieve a focusing effect close to that of the lens-moving actuator.

Further, as shown in FIG. 9 , when the lens-moving actuator and the actuator of the present invention are used at the same time, the focusing distance can be further reduced and the maximum magnification of the photographing device can be increased. When a lens-moving actuator is used, the lens can increase ΔD1, and the distance between the lens and the image sensor can also increase ΔD1; when both the lens-moving type and the actuator in the present invention are used, the actuator in the present invention The image sensor ΔD2 can be moved down, which can additionally increase the distance ΔD2 between the lens and the image sensor, resulting in a smaller minimum focus distance.

The above description of the present invention is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the present invention. within the scope of protection of the invention.

Claims (10)

1. A split type low-power-consumption small-sized automatic focusing brake is characterized by comprising a shell, a spring, an image sensor carrier, at least one magnet, at least one independent coil and an elastic circuit board, wherein the spring is arranged on the inner surface of the top of the shell and can elastically deform along the vertical axis direction of the shell;

the at least one magnet is arranged on the inner wall of the shell, the independent coil is arranged on the image sensor carrier and corresponds to the magnet, and the independent coil is electrified to be acted by ampere force in a magnetic field of the magnet.

2. The split type low power consumption small auto-focus brake of claim 1, wherein an image sensor is disposed on the elastic circuit board.

3. The split type low-power-consumption small-sized automatic focusing brake as claimed in claim 1, further comprising a positioning seat abutting against the inner top surface and the inner wall of the housing, wherein the positioning seat fixes the at least one magnet on the inner wall of the housing;

the spring is a spring piece, one end of the spring piece is fastened at the joint of the inner top surface of the shell and the positioning seat, and the other end of the spring piece is connected with the image sensor carrier.

4. The brake of claim 3, wherein the flexible printed circuit board includes a first to a fifth rigid printed circuit boards, a first flexible printed circuit board, and a second flexible printed circuit board, the first rigid printed circuit board carries the image sensor and the periphery of the first rigid printed circuit board is connected to the first flexible printed circuit board, four corners of the first flexible printed circuit board are respectively connected to the second to the fifth rigid printed circuit boards, the second to the fifth rigid printed circuit boards are further respectively connected to the second flexible printed circuit board, and the second flexible printed circuit board is provided with a socket.

5. The split type low-power-consumption small-sized automatic focusing brake as claimed in claim 4, wherein the image sensor carrier is rigidly connected to the first rigid circuit board, and the second to fifth rigid circuit boards are also rigidly connected to the positioning seats, respectively.

6. The split type low-power consumption small-sized automatic focusing brake of claim 1, further comprising a cylindrical partition, the cylindrical partition being coaxially disposed with the vertical axis of the housing, and having an upper end connected to or integrally formed with the upper surface of the housing, the cylindrical partition further having a gap with the image sensor carrier.

7. The brake of claim 6, wherein the cylindrical partition is made of a material with good magnetic and thermal conductivity, and the surface color of the cylindrical partition is a dark color with strong heat radiation absorption capability.

8. The split type low power consumption small auto-focus brake according to claim 6, wherein the height of the cylindrical partition plate is more than one third of the height of the magnet.

9. The split type low power consumption small auto-focus brake of claim 1, wherein when the number of the magnets is more than 1, like magnetic poles of the magnets are oppositely arranged.

10. The split type low-power-consumption small-sized automatic focusing brake as claimed in claim 3, wherein the periphery of the image sensor carrier is further provided with a limiting boss; and positioning holes with coincident hole positions are formed in the upper surface of the shell and the upper surface of the positioning seat.

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